Brainstem infarct with pharyngeal dysmotility and paralyzed vocal cord: management with a multidisciplinary approach.

An unusual case of right posterior brainstem infarction with isolated deficits of severe dysphagia and ataxia is presented. Neurological examination revealed dysfunction of the pharyngeal and laryngeal branches of cranial nerves IX, X, and a paralyzed right vocal cord. The patient was unable to swallow 1/4 teaspoon of applesauce. Modified barium swallow revealed extremely sluggish pharyngeal peristalsis and absent swallowing reflex. Percutaneous esophageal gastrostomy tube was inserted and an intensive dysphagia rehabilitation program was initiated. Pharyngeal-phase-oriented protocol was used. Results were significantly improved compensatory pharyngeal and laryngeal function with restoration of swallowing and no aspiration. This case illustrates successful management of dysphagia associated with brainstem infarction and the benefits of a coordinated multidisciplinary protocol.

Plasma adenosine changes during cardiac surgery.

Changes in plasma adenosine and inosine were measured during high-dose narcotic anesthesia and surgery for coronary artery bypass grafting (CABG), and mitral or aortic valve replacement (V). Arterial and mixed venous blood samples were obtained for measurement of adenosine and inosine at eight sampling intervals ranging from preanesthesia induction to discontinuation of cardiopulmonary bypass (CPB). Arterial but not mixed venous adenosine was markedly elevated in blood samples 10 minutes after intubation, but the fourfold elevation was significant only in the CABG patient group. Mixed venous inosine and adenosine were most consistently elevated in post-CPB samples. In a separate study of arterial adenosine changes during induction, a uniform drug administration protocol was used, and again adenosine was significantly increased immediately after intubation. It is possible that adenosine and perhaps inosine may contribute to cardiovascular responses following induction-intubation and also after discontinuing CPB.

Hypothyroidism delays ischemia-induced contracture and adenine nucleotide depletion in rat myocardium.

Isolated perfused paced hearts from rats rendered hypothyroid by chronic administration of propylthiouracil have a delayed onset of ischemia-induced myocardial contracture in contrast to hearts from control rats. In addition, the time to reach maximum contracture is delayed, and the magnitude of the contracture pressure is reduced. Preischemia myocardial adenosine triphosphate (ATP) values in the hypothyroid rat hearts are similar to those of control, but the rate of decrease in ATP is slower in the hearts of hypothyroid rats. Thus, it appears that in the hypothyroid state the development of ischemic contracture is associated with a slower fall of ATP.

Hyperkalemia and cardiovascular collapse after verapamil and dantrolene administration in swine.

The cardiovascular and neuromuscular interactions of verapamil and dantrolene were evaluated in 20 chloralose-anesthetized swine. The animals were randomly divided into three groups. Group I, ten animals, received a bolus intravenous injection of 0.1 mg . kg-1 of verapamil followed by the continuous infusion of 5 micrograms . kg-1 . min-1. This group was then randomly divided into two equal subgroups. Five of these animals, Group Ia, continued to receive the verapamil infusion alone. The other five animals, Group Ib, received dantrolene in incremental doses of 1.0, 3.3, and 5.6 mg . kg-1 while the verapamil infusion was continued. An additional group of five animals, Group II, received the same incremental doses of dantrolene but did not receive verapamil. Five control animals, Group III, received the alpha-chloralose anesthetic without dantrolene or verapamil. Neuromuscular function, as measured by twitch height, was affected only by dantrolene, which produced a dose-dependent depression. Verapamil resulted in initial decreases in heart rate, arterial blood pressure, cardiac output, left ventricular dP/dt, and an increase in PR interval. Dantrolene alone produced a mild increase in arterial blood pressure. Dantrolene administration to verapamil-pretreated animals resulted in a profound depression in cardiac function, marked elevation in serum K+ (8.0 +/- 0.7 mEq . l-1), and no change in arterial pH (7.39 +/- 0.02). Cardiac arrest preceded by complete atrioventricular heart block occurred in one animal before and in four animals after the final dantrolene dose was given to animals pretreated with verapamil. Although we cannot extrapolate data from our porcine model to humans, further studies are indicated to help evaluate a possible fatal drug interaction before verapamil and dantrolene are used concomitantly in a clinical setting.